The Atmosphere

Unit Review Sheet

Facts and Definitions

Lesson 1: What Is the Atmosphere?

• The atmosphere is made of matter, which means it has mass and takes up space.
• The atmosphere is made of gases, including nitrogen, oxygen, and carbon dioxide.
• The atmosphere is part of a larger Earth system and interacts with land, water, and energy.
• The way the atmosphere interacts with energy affects conditions on Earth, including temperature and the ability to support life.
• The atmosphere is the layer of gases that surrounds Earth and supports life.
• Trace gases are gases in the atmosphere that are present in very small amounts but can still have important effects (such as carbon dioxide and water vapor).

Lesson 2: Layers of the Atmosphere

• The atmosphere is divided into the following layers in the following order from the Earth's surface: troposphere, stratosphere, mesosphere, thermosphere, and exosphere.
• Troposphere: Nearly all weather occurs in the troposphere.
• Stratosphere: The ozone layer is located in the stratosphere and absorbs most harmful ultraviolet (UV) radiation from the Sun.
• Mesosphere: Most meteors burn up in the mesosphere.
• Thermosphere: Auroras occur in the thermosphere, and the International Space Station orbits there.
• Exosphere: The exosphere is the outermost layer of Earth's atmosphere and gradually fades into outer space.
• Layers in the atmosphere have different temperatures. The structure and composition of the atmosphere influence temperature and conditions at different altitudes.
• The ozone layer is a region in the stratosphere that contains a high concentration of ozone gas and absorbs most of the Sun's harmful ultraviolet (UV) radiation, helping protect life on Earth.

Lesson 3: Air Pressure and Density

• Density describes how closely packed particles are in a substance.
• As temperature increases, air pressure can decrease as air particles move faster and spread farther apart, becoming less dense.
• Altitude is how high a place is above Earth's surface. Higher altitudes usually have lower air pressure.
• Temperature measures the warmth or coolness of matter.
• Air pressure (also called atmospheric pressure) is the force created by the weight of air molecules pressing down on a surface. A barometer measures air pressure.
• Scientists collect and analyze data on sky conditions to help predict future weather.
• Changes in air pressure can lead to various weather phenomena in the atmosphere. Low-pressure systems often bring storms and precipitation, while high-pressure systems are usually associated with clear skies and calm weather.

Lesson 4: Energy from the Sun

• The Sun provides energy to the Earth which interacts with Earth's surface and atmosphere as part of a larger system.
• Different surfaces absorb and reflect heat energy at different rates.
• Water absorbs more energy than land.
• Energy from the Sun can be absorbed by Earth's surface or by gases in the atmosphere before it reaches the surface.
• Radiation is the transfer of energy through electromagnetic waves, like sunlight.
• Radiation from the Sun is the primary source of energy for Earth's weather and climate systems.
• Absorption is when a surface takes in energy, causing it to warm up.
• Reflection is when energy bounces off a surface instead of being absorbed.
• Albedo is a measure of how much energy a surface reflects.
• Surfaces with high albedo reflect more energy, while surfaces with low albedo absorb more.

Lesson 5: Heat Transfer in the Atmosphere

• Energy from the Sun enters Earth's system and moves between the surface and the atmosphere.
• This movement of energy drives interactions in the atmosphere, including changes in air temperature and motion.
• Heat energy moves in three main ways: radiation, conduction, and convection.
• Radiation does not require matter to travel.
• The Sun's energy traveling to Earth is an example of radiation.
• Conduction transfers heat through direct contact, such as between Earth's surface and the air above it.
• Convection transfers heat through the movement of air.
• Warm air rises and cool air sinks, creating convection currents in the atmosphere.
• Uneven heating of Earth's surface causes differences in temperature, which leads to air movement.
• Air currents are moving masses of air that change weather patterns.
• Convection cells form when air continuously rises and sinks in a repeating pattern.
• A land breeze is a wind that blows from land toward water at night because land cools faster than water.
• A sea breeze is a wind that blows from water toward land during the day because land heats faster than water.

Lesson 6: Wind and Global Circulation

• Uneven heating of the Earth and the rotation of the Earth create wind patterns.
• Wind is the horizontal movement of air parallel to the Earth's surface and is described by its speed and direction.
• The Coriolis effect is the phenomenon in which moving air appears to curve rather than travel in a straight line because Earth is constantly spinning. In the Northern Hemisphere, winds curve to the right, and in the Southern Hemisphere, winds curve to the left.
• Trade Winds are steady winds that blow near the Equator, moving from areas of high pressure toward low pressure. They curve as they travel because of Earth's rotation, creating consistent global wind patterns.
• A Jet Stream is a fast-moving band of air high in the atmosphere that flows from west to east. It forms due to differences in temperature and helps move weather systems, such as storms, across the planet.

Lesson 7: Air Masses and Weather Systems

• Air masses are large bodies of air with similar temperature and moisture, and weather fronts are the boundaries where different air masses meet.
• When air masses move and meet, they cause changes in weather and can create storms.
• Scientists predict severe weather using radar, satellites, and forecasting models, and its impacts can be reduced through monitoring and preparation.
• A tornado is a fast-spinning column of air that forms from a thunderstorm when warm air rises into cold air and reaches the ground, causing strong, damaging winds.
• A hurricane is a large, rotating storm that forms over warm ocean water, fueled by rising warm air, and brings strong winds, heavy rain, and flooding.
• Doppler radar is a tool that uses radio waves to detect precipitation and measure how fast and in what direction storms are moving.
• A satellite is an object in space that takes images of Earth's atmosphere, helping scientists track large weather systems like hurricanes.
• A blizzard is a winter storm with strong winds over 35 mph, heavy snow, and near-zero visibility.
• Winds at different heights in the atmosphere may also move in different directions or at different speeds. This is called wind shear.

Lesson 8: Human Impact on the Atmosphere

• Air pollution can harm the environment and human health, and human activities can change the quality of the air and atmosphere.
• Humans have a shared responsibility to reduce their carbon footprint because increased greenhouse gases are causing Earth's temperature to rise over time.
• A carbon footprint is the total amount of greenhouse gas emissions produced by the activities of a person, organization, event, or product.
• Stewardship is our shared responsibility to care for and protect the environment.
• Climate change is a long-term change in Earth's temperature and weather patterns, largely caused by an increase in greenhouse gases in the atmosphere.
• Fossil fuels are natural fuels such as coal, oil, and natural gas that formed from the remains of ancient plants and animals and release energy when burned.
• Renewable energy is energy that comes from natural sources that can be replaced over time, such as sunlight, wind, and water.

Final Project: Atmosphere Escape Room Challenge

• [none]